a picnic table on a beach near a body of water
Founders Park is under a swim advisory due to high levels of bacteria in the nearshore waters. DAVID GROSS/Keys Weekly

Several Florida Keys beaches are under swim warnings due to the high presence of bacteria in the nearshore waters. 

On June 20, the Florida Department of Health in Monroe County said beach water quality testing performed at beaches and parks found elevated levels of enteric bacteria (enterococci) in the nearshore waters at six locations. They include Founders Park Beach in Islamorada, Sombrero Beach in Marathon, Bahia Honda oceanside beach, as well as Higgs, Smathers and South beaches in Key West.  

“The presence of enteric bacteria is an indication of fecal pollution, which may come from stormwater runoff, pets, wildlife and human sewage,” states a press release from the health department. “These bacteria may cause human disease, infections or rashes.”

The health department continues to advise the public to avoid swimming or practicing other water-related activities in the nearshore waters at these locations until bacteriological results show the water is safe for recreating. High concentrations of bacteria in waters could cause swimmers to have rashes and infections. 

The U.S. EPA’s recommended standards classify water containing 0-35 enterococcus bacteria per 100 milliliters of water as “good,” 36-70 as “moderate” and 71 or greater as “poor.” Though a “poor” water quality test may not close a beach, the department issues an advisory for potential health risks in areas with water in the “poor” range.

Per the beach monitoring report, high levels of enterococcus were found at Higgs Beach, 659, and South Beach, 483. Poor water quality was also reported at Bahia Honda oceanside, 124, Smathers Beach, 99, Sombrero Beach, 87, and Founders Park, 75. While no advisories were issued, water quality was deemed “moderate” at Harry Harris Park, 42, and Fort Zachary Taylor State Park, 53. Bahia Honda bayside beach, 1, and John Pennekamp State Park, 31, had relatively low levels of enterococcus and water quality deemed “good.” Anne’s Beach in Islamorada wasn’t tested at the time of publication.